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The Green's function method and superconductivity of systems of fermions

Jerzy Sawicki

Annals of PhysicsMay 1, 19615 citations

Potential Electron Scattering by Phosphorus Atom

Irina Bariakhtar, Alexander Nazarenko

The normal state temperature one- and two-particle Green’s functions are calculated within the framework of the conserving self-consistent approximation accounting for the fluctuations in the particle-particle channel for the attractive Hubbard model. The Pad´e continuation to the complex plane is used to study the pole structure of the retarded one-particle Green’s function. The momentum and temperature dependences of the positions of the leading quasiparticle poles are consistent with Bogolyubov’s picture, when the second leading pole emerges and rapidly moves toward the real axes. The non-Fermi liquid behavior of the first leading pole is detected at the intermediate coupling. The two-particle Green’s function is used to calculate the temperature dependence of the uniform static spin susceptibility, which is shown to exhibit the diamagnetic tendency, as the system approaches the superconducting phase transition.The normal state temperature one- and two-particle Green’s functions are calculated within the framework of the conserving self-consistent approximation accounting for the fluctuations in the particle-particle channel for the attractive Hubbard model. The Pad´e continuation to the complex plane is used to study the pole structure of the retarded one-particle Green’s function. The momentum and temperature dependences of the positions of the leading quasiparticle poles are consistent with Bogolyubov’s picture, when the second leading pole emerges and rapidly moves toward the real axes. The non-Fermi liquid behavior of the first leading pole is detected at the intermediate coupling. The two-particle Green’s function is used to calculate the temperature dependence of the uniform static spin susceptibility, which is shown to exhibit the diamagnetic tendency, as the system approaches the superconducting phase transition.

Ukrainian Journal of PhysicsJun 1, 20140 citations

THEORY OF PHASE TRANSITION IN FERMI SYSTEMS

D.N. Zubov, Yu. A. Tserkovnikov

Jan 1, 19590 citations

PHASE FLUCTUATIONS AND NON-FERMI LIQUID PROPERTIES OF 2D FERMI-SYSTEM WITH ATTRACTION

V. P. Gusynin, VADIM M. LOKTEV, RACHEL M. QUICK +1 more

The effect of static fluctuations in the phase of the order parameter on the normal and superconducting properties of a 2D system with attractive four-fermion interaction has been studied. Analytic expressions for the fermion Green function, its spectral density and the density of states are derived. The resultant single-particle Green function clearly demonstrates non-Fermi liquid behavior. The results show that as the temperature increases through the 2D critical temperature the width of the quasiparticle peaks broadens significantly. At the same time one retains the gap in quasiparticle spectrum. The spectral density for the dynamical fluctuations can also be obtained. Clearly the dynamical fluctuations fill the gap giving the observed pseudogap behaviour.The effect of static fluctuations in the phase of the order parameter on the normal and superconducting properties of a 2D system with attractive four-fermion interaction has been studied. Analytic expressions for the fermion Green function, its spectral density and the density of states are derived. The resultant single-particle Green function clearly demonstrates non-Fermi liquid behavior. The results show that as the temperature increases through the 2D critical temperature the width of the quasiparticle peaks broadens significantly. At the same time one retains the gap in quasiparticle spectrum. The spectral density for the dynamical fluctuations can also be obtained. Clearly the dynamical fluctuations fill the gap giving the observed pseudogap behaviour.

arXiv:cond-mat/9906407International Journal of Modern Physics BDec 20, 19991 citation

Phase fluctuations and Non-Fermi Liquid Properties of 2D Fermi-system with attraction

V. P. Gusynin, В. М. Локтев, R. M. Quick +1 more

The effect of static fluctuations in the phase of the order parameter on the normal and superconducting properties of a 2D system with attractive four-fermion interaction has been studied. Analytic expressions for the fermion Green function, its spectral density and the density of states are derived. The resultant single-particle Green function clearly demonstrates non-Fermi liquid behavior. The results show that as the temperature increases through the 2D critical temperature the width of the quasiparticle peaks broadens significantly. At the same time one retains the gap in quasiparticle spectrum. The spectral density for the dynamical fluctuations can also be obtained. Clearly the dynamical fluctuations fill the gap giving the observed pseudogap behaviour.The effect of static fluctuations in the phase of the order parameter on the normal and superconducting properties of a 2D system with attractive four-fermion interaction has been studied. Analytic expressions for the fermion Green function, its spectral density and the density of states are derived. The resultant single-particle Green function clearly demonstrates non-Fermi liquid behavior. The results show that as the temperature increases through the 2D critical temperature the width of the quasiparticle peaks broadens significantly. At the same time one retains the gap in quasiparticle spectrum. The spectral density for the dynamical fluctuations can also be obtained. Clearly the dynamical fluctuations fill the gap giving the observed pseudogap behaviour.

Jan 1, 19991 citation

Perturbation theory for superconducting Fermi systems

Victor Nikolaevich Popov

Cambridge University Press eBooksJan 7, 19880 citations

Temperature Green’s functions in Fermi systems: The superconducting phase transition

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